George Kukla, a climate scientist who was among the first to warn of the power of global climate change and inspire government study, died on May 31 at his home in Suffern, N.Y. The cause was an apparent heart attack; he was 84.

Some 56 million years ago, a massive pulse of carbon dioxide into the atmosphere sent global temperatures soaring. In the oceans, carbonate sediments dissolved, some organisms went extinct and others evolved.

Scientists have long suspected that ocean acidification caused the crisis—similar to today, as manmade CO2 combines with seawater to change its chemistry. Now, for the first time, scientists have quantified the extent of surface acidification from those ancient days, and the news is not good: the oceans are on track to acidify at least as much as they did then, only at a much faster rate.

As the last ice age was ending, about 13,000 years ago, a final blast of cold hit Europe, and for a thousand years or more, it felt like the ice age had returned. But oddly, despite bitter cold winters in the north, Antarctica was heating up. For the two decades since ice core records revealed that Europe was cooling at the same time Antarctica was warming over this thousand-year period, scientists have looked for an explanation.

Every day since Jan. 1, 1896, an observer has hiked up a grey outcrop of rock to a spot at The Mohonk Preserve, a resort and nature area some 90 miles north of New York City, to record daily temperature and other conditions there.

Scientists broadly agree that global warming may threaten the survival of many plant and animal species; but global warming did not kill the Monteverde golden toad, an often cited example of climate-triggered extinction, says a new study.

A new study adds evidence that climate swings in Europe and North America during the last ice age were closely linked to changes in the tropics. The study, published this week in the journal Science, suggests that a prolonged cold spell...

Researchers have reconstructed atmospheric carbon dioxide levels over the past 2.1 million years in the sharpest detail yet, shedding new light on its role in the earth’s cycles of cooling and warming.

A power plant in Iceland is set to become the first in the world to try turning carbon dioxide emissions into solid minerals underground, starting this September.

In an $11 million pilot project, Reykjavik Energy will capture CO2 from its plant, dissolve the gas in water and inject it deep into volcanic basalt nearby. Over the nine-month study, some 2,000 tons of greenhouse gas will be treated.

Researchers have developed the first year-by-year record of rainfall in sub-Saharan West Africa for the past 3,000 years, and identified a daunting pattern: a 30-to-60-year cycle of serious droughts that last a decade or more, punctuated by killer megadroughts that last for centuries.

Climate researchers have shown that big volcanic eruptions over the past 450 years have temporarily cooled weather in the tropics—but suggest that such effects may have been masked in the 20th century by rising global temperatures

A study released on May 11, 2007 provides some of the first solid evidence that warming-induced changes in ocean circulation at the end of the last Ice Age caused vast quantities of ancient carbon dioxide to belch from the deep sea into the atmosphere. Scientists believe the carbon dioxide (CO2) releases helped propel the world into further warming.

Seismologists at Columbia University and Harvard University have found a new indicator that the Earth is warming: "glacial earthquakes" caused when the rivers of ice lurch unexpectedly and produce temblors as strong as magnitude 5.1 on the moment-magnitude scale, which is similar to the Richter scale. Glacial earthquakes in Greenland, the researchers found, are most common in July and August, and have more than doubled in number since 2002.